YBCO高温超导线圈绝缘和加固新方法的内在机制研究

大量实验研究发现，由于热收缩系数的不匹配，环氧浸渍的YBCO高温超导线圈在多次冷热循环后会出现不同程度临界电流性能退化，严重制约了其在高场磁体中的应用。不同类型环氧树脂、石蜡、热缩管、以及无绝缘等多种方式均被尝试作为高温超导线圈的绝缘材料，以解决高温超导线圈性能退化问题。但各种方法均有各自的优缺点，新的绝缘和加固方式仍需探索。申请人结合稳态强磁场和脉冲强磁场技术，在国际上首次提出将冰线圈技术应用到高温超导磁体的思想，并实验验证了其可行性。利用超冷冰作为绝缘材料，实验表明高温超导线圈得到了很好的加固和绝缘，且经过多次冷热循环后没有出现任何的临界电流性能退化，然而冰对超导线圈性能的影响机制尚不明确，技术细节也有待深入研究和提高。本项目拟针对YBCO超导线圈绝缘和加固的新方法展开研究，明确冰线圈的内在原理和作用机制，探索YBCO高温超导磁体浸渍的新技术，推动高温超导线圈在高场磁体中的应用。

A large number of experimental studies have found that there is critical current performance degradation with different degrees for epoxy impregnated YBCO high temperature superconducting coil after thermal cycles, whichh seriously restricts its application in high field magnets. Different types of epoxy resin, paraffin, heat shrinkable tube and non-insulation were tried to be used as the insulation of high temperature superconducting coil, so as to solve the performance degradation of high temperature superconducting coil. However, each method has its own advantages and disadvantages, new insulation and reinforcement methods still need to be explored. The applicant proposed the idea of applying ice coil technology to high temperature superconducting magnet for the first time in the world by combining the steady-state high magnetic field and pulse high magnetic field technology, and the feasibility was verified by experiments. Ice was used as the insulation of high temperature superconducting coil, the experimental results showed that the high temperature superconducting coil is well reinforced and insulated, and there is not any critical current performance degradation after thermal cycles. But the mechanism of the influence of ice on the performance of superconducting coils is not clear, and the technical details need to be further studied and improved. This project aims to study the new methods of insulation and reinforcement of YBCO superconducting coil, clarify the internal principle and mechanism of ice coil, explore the new impregnation technology of YBCO high temperature superconducting magnet, and promote the wide application of high temperature superconducting coil in high field magnet.